SUMMARY After upgrade to 6.5.4 screen locker no longer works properly. I can't enter password. Mouse click doesn't work. Second screen is black. Only thing that works is mouse move. If I move mouse off screen, password field goes away. STEPS TO REPRODUCE 1. Lock screen OBSERVED RESULT System no longer accessible. Only hard reset is possible. EXPECTED RESULT System not doing this? SOFTWARE/OS VERSIONS Operating System: Arch Linux KDE Plasma Version: 6.5.4 KDE Frameworks Version: 6.20.0 Qt Version: 6.10.1 Kernel Version: 6.17.9-arch1-1 (64-bit) Graphics Platform: Wayland Processors: 8 × Intel® Core™ i7-8705G CPU @ 3.10GHz Memory: 32 GiB of RAM (31.3 GiB usable) Graphics Processor 1: AMD Radeon RX Vega M GL Graphics Graphics Processor 2: Mesa Intel® HD Graphics 630 ADDITIONAL INFORMATION There are repeatable log messages from kwin_wayland from before I hit reset: kwin_wayland[1029]: Atomic modeset test failed! Invalid argument kwin_wayland[1029]: Setting dpms mode failed! I've got them from journald after reset.
My system is affected the same way on Gentoo. Operating System: Gentoo Linux 2.18 KDE Plasma Version: 6.5.4 KDE Frameworks Version: 6.20.0 Qt Version: 6.10.1 Kernel Version: 6.18.0-gentoo (64-bit) Graphics Platform: Wayland Processors: 16 × AMD Ryzen 7 3800X 8-Core Processor Memory: 64 GiB of RAM (62.7 GiB usable) Graphics Processor: AMD Radeon RX 580 Series Manufacturer: Gigabyte Technology Co., Ltd. Product Name: X570 AORUS ELITE
I'm also seeing something fairly similar: https://bugs.kde.org/show_bug.cgi?id=511118#c4
I'm also seeing something similar ("Atomic modeset test failed! Invalid argument" and "Setting dpms mode failed!" repeated messages occurring after upgrading to Plasma 6.5.4), but in my case those messages appear if I lock my screen and turn it off by pressing Esc, then I won't be able to do anything (not even Ctrl+Alt+F1/2/3/4/5/6/7) other than Magic SysRq stuff. Reverting KWin specifically to 6.5.3 gets rid of my issue, and I was able to bisect it to this commit: https://invent.kde.org/plasma/kwin/-/commit/0dd26bc3e013492eb92fe934cfd49636cf9219a3 (Use correct DBus interface for inhibiting sleep) from MR https://invent.kde.org/plasma/kwin/-/merge_requests/8454 Reverting that commit on top of KWin 6.5.4 fixes my problem, and if I apply that patch to KWin 6.5.3 the problem reappears, so I'm fairly certain that commit is indeed what is causing my issue, although it could be that it's just exposing a different bug somewhere else. Operating System: Arch Linux KDE Plasma Version: 6.5.4 KDE Frameworks Version: 6.20.0 Qt Version: 6.10.1 Kernel Version: 6.17.9-arch1-1 (64-bit) Graphics Platform: Wayland Processors: 18 × Intel® Core™ Ultra 5 125H Memory: 32 GiB of RAM (30.8 GiB usable) Graphics Processor: Intel® Arc Manufacturer: Framework Product Name: Laptop 13 (Intel Core Ultra Series 1) System Version: A2
I cannot reproduce this on current git master, FWIW. Operating System: KDE Linux 2025-12-08 KDE Plasma Version: 6.5.80 KDE Frameworks Version: 6.22.0 Qt Version: 6.10.1 Kernel Version: 6.17.9-arch1-1 (64-bit) Graphics Platform: Wayland Processors: 16 × AMD Ryzen 7 7840U w/ Radeon™ 780M Graphics Memory: 17 GB of RAM (16.0 GB usable) Graphics Processor: AMD Radeon 780M Graphics
I'm also getting similar weirdness with Wayland on Plasma 6.5.4. If the display locks and the display sleep timer hits, keyboard and mouse input will wake the display to a backlit black screen, but nothing displays. If I manually power the display back off, wait a few seconds, and power back on, the lock screen is displayed normally and I can get back into the system. This is a desktop with a single display, everything running through my AMD dGPU. This doesn't seem to occur on X11, though I've only tested a couple of display-only sleep/wake cycles thus far. Journalctl gives a bunch of "Atomic modeset test failed! Invalid argument." and "Setting dpms mode failed!" messages as the other users have seen. I am reticent to update my work laptop to 6.5.4 to further test (it's on a Ryzen 5000 series APU), but I have a spare older laptop with an Intel iGPU I can slap it onto if needed to check for interactions with certain hardware. @Nate Graham - would the fact this isn't reproducible in the latest git main indicate the bug has been resolved and is waiting for 6.5.5? System info: Operating System: Arch Linux KDE Plasma Version: 6.5.4 KDE Frameworks Version: 6.20.0 Qt Version: 6.10.1 Kernel Version: 6.17.9-arch1-1 (64-bit) Graphics Platform: Wayland Processors: 24 × AMD Ryzen 9 9900X 12-Core Processor Memory: 32 GiB of RAM (30.9 GiB usable) Graphics Processor: AMD Radeon RX 7800 XT Manufacturer: ASRock Product Name: B850M Pro RS WiFi
*** This bug has been marked as a duplicate of bug 513151 ***